Magnetic sheet feeder



Nov. 24,1959 w. D. BRAINARD 2,914,324

MAGNETIC SHEET FEEDER Filed June 6, 1956 4 Sheets-Sheet 1 l/VVENTOR.WILSON D. BRm/vmm arm ELM Arrokusx Nov. 24, 1959 I w. D; BRAINARD h I ,9

MAGNETIC SHEET FEEDER I Filed June e. 1956 I sheets-sheet 2 f 3 I E ImwsA/rop W11. 60M 0. ERMA/4P0 Nov. 24, 1959 w. D. BRAINARD MAGNETICSHEET FEEDER r m y E t T N e m 0 54 r w WM m m 0 w 4 M a ls M Y 8 g QM.

Filed June 6, 1956 Nov. 24, 19 59 ,W. D. BRAINARD 2,914,324

MAGNETIC SHEETYFEEDIER 4 Sheets Sheet 4 Filed June 6, 1956 mm Mm a I/YVE/YTOR. WILSON D. Rpm/V400 ATTOR/YEK' Unitd States MAGNETIC SHEETFEEDER Wilson D. Brainard, Franklin Square, N.Y., assignor of fiftypercent to Owen Brainard, Des Moines, Iowa Application .iune 6, 1956,Serial No. 589,803

8 Claims. (Cl. 27184) My invention relates to improvements in silkscreen machines.

The instant invention contemplates a silk screen ma chine that willmaterially increase the speed and efficiency of operation as compared topresent machines of a like nature. As will later appear I havepreferably shown it as working semi-automatically but it will beunderstood that full automatic operation can be obtained withoutdeparting from the principle thereof.

Another object of this invention is to provide in a silk screen machinea novel means for transferring paper or other material to be printed,from one position to another.

Still another object inhering herein is the provision in a silk screenmachine of simultaneously effecting the movement of three separatesheets of paper, namely, the sheet on the drying plate, the sheet on theprinting surface and a sheet from the supply stack.

Another important object of this invention is to provide a magneticpaper gripping means for use with a machine of the above class.

Other objects and advantages of this invention reside in the details ofconstruction and correlation of the various parts and will be apparentas the description proceeds.

This invention consists of novel parts and combination of parts to behereinafter described whereby the objects set forth are attained, aspointed out in the claims, and illustrated in the accompanying drawings,in which:

Fig. 1 is a perspective view showing a preferred form of my invention,

Fig. 2 is an enlarged top view of this machine showing theframed screenin printing position,

Fig. 3 is an enlarged side view of the magnetic paper gripper taken fromthe line 33 of Fig. 2 and showing it in closed contact with a sheet ofpaper,

Fig. 4 is a top view similar to Fig. 2 but showing the framed screenmoved away from its printing position,

Fig. 5 isa side view similar to Fig. 3 but showing the open position ofthe gripper when moved correspondingly to the position of the framedscreen in Fig. 4.

Fig. 6 is an enlarged perspective view of a flap valve used with the airhose in this machine.

Fig. 7 is a fragmentary side view of one of the tracks taken on the line7-7 of Fig. 2 and showing the lower position of the drying plate,

Fig. 8 is a view similar to Fig. 7 but showing the raised or elevatedposition of the drying plate, and,

Fig. 9 is an enlargedfragmentary elevational view partly in sectiontaken on the line 99 of Fig. 4 and showing the paper supply table andelevating means therefor.

Referring to the drawings a box-like supporting base 10 houses asuitable motor and pump (not shown) for use in providing suction as willlater appear. A pair of parallel side boards 12 and 14 forming a part ofbase 1d are mounted to respective opposite sides thereof (Fig. 1)andproject from opposite ends thereof as shown. End

Patented Nov. 24, 1959 braces 16 connect the side boards 12 and 14 ateach end and carry the respective tracks 18 and 20 that aresubstantially co-extensive in length with each side board and adjacentthe same. A cross member 22 rests on top of rails 18 and 20 between theright ends of boards 12 and 14 as viewed in Fig. 1, which end forpurposes of clarity will be referred to as the rear 24 to distinguish itfrom the left side of Fig. 1 which I shall call the front or forward end26.

A printing surface or board or paper supporting platform 28 (Fig. 1) ismounted between boards 12 and '14 and approximately midway between thefront 26 and rear 24 thereof and is provided with a beveled notch 36toward the front end 26. Between the rear portions 'of side boards 12and 14 (Fig. 9) a horizontal base 32 is placed for supporting a supplyof paper 34 and is pro-' vided with depending Wedge shaped sides 36which are progressively narrower in depth toward end 24 as shown. Sides36 are slidably rested on respective wedge sides 38 of a U-shaped frame4i having its closed end extending between boards 12 and 14 at end 24.Frame 40 is mounted so as to be slidable towards end 26 for raising base32 as will be later explained in detail. A shaft 42 is mountedtransversely of boards 12 and 14 just forwardly of base 32 and carries acable 44 wound thereon and extending to a point of attachment 46 onframe 40 at end 24. Shaft 42 carries a ratchet wheel 48 on one end nearside board 14 and a resilient pawl 50 engages wheel 48 as shown.

At the forward end 26 of this machine I have mounted a drying unitindicated generally at 52. This comprises .an electric heating element54 carried on a downwardly inclined support 56 firmly aiiixed to thefront side of base 10. At the lower end of support 56 is an upnstandingbaffie or stop 58 and in endwise alignment with and as an extension ofthe support 56 there is placed an open top receiving tray member 60. Adrying board or plate 62 having good thermal conducting ability and thuspreferably made of aluminum lies over the heating element 54 insubstantially a parallel plane with support 56 and is hingedly securedas at 64 to the respective boards 12 and 14. Rigidly connected to plate62 at its hinge point near board 14 is a bar or lever 66 that isdisposed adjacent and substantially parallel to track 18. Lever 66extends towards end 24 of this machine and is provided on its free endwith the vertical shoulder 68 followed by the inclined surface 749. Thisarrangement as will later be described more in detail is to provide atilting of lever 66 and plate 62 about hinge 64 as a pivot point wherebyplate 62 is raised and lowered relative to the top of baffie 53.Suspended over the plate 62 and supported from the brace 16 is an infrared heat lamp 71 which together with element 54 supplies heatsimultaneously to both sides of plate 62.

A carriage or frame indicated generally at 72 (Figs. 2 and 4) is movablymounted on tracks 18 and 26. It is generally U-shaped having the sides74 and 76 which carry wheels '78 at each end; a cross member 80 at oneend positioned relative to the forward end 26 of this machine and asecond cross member 32 substantially midway between the ends of sides 74and 76 to provide carriage openings 34 and 86. A frame 88 containing asilk screen 96 is hinged to carriage frame side 74 so that it can beraised and lowered into opening 84 (Fig. 1). A spring means 92 connectsscreen frame 88 to the carriage side 74 so as to normally urge it toopen or raised position. To the opposite side of screen frame 88 a cordor cable 94 extends over a pulley 96 mounted on sideboard 12 and carriesa weight 98 on its free end which hangs suspended along side base 10.

A suction pickup foot 100 is mounted on crossbar 82 of the carriage soas to communicate with opening 84 'the bar member 110 which extendstherefrom across the crossbar 82 and over opening 86 where it carries aroller 112 on its free end. Bar 110 also contains a counterbalance 114and is hingedly connected as at 116 to an underlying bar 118 projectinginto opening 86 from crossbar 82. Thus it will be seen that foot 100 hasa certain range of vertical movement by rocking on point 116. On brace22 at the rear end 24 of this machine, an arm 120 is mounted to extendtoward roller 112 and in line therewith. The free end of arm 120 isinclined downwardly to form a ramp 122 so that as the carriage is movedtoward end 24, roller 112 will ride up ramp 122 and lower .the suctionfoot 100.

With reference now more particularly to Figs. 3 and I will describe mymagnetic paper gripping jaw assembly which is one of the important novelelements on this machine. As shown this gripper member or jaw assemblyindicated generally at 124 is used for removing a sheet of paper 126from the printing surface 28 for transfer to the drying plate 62 but itwill be understood that a gripper of this type can also be used fortransferring paper from stack 34 to the printing surface 28 instead ofthe suction foot 100 as will later appear. Gripper 124 is mounted to thecentral underside of cross member 80 of the carriage frame and comprisesan elongated block 128 secured transversely of the longitudinal axisthereof. A steel plate 130 is secured to the bottom of block 128 so asto project into opening 84 and carries a claw point 132 on its free end.A second block 134 is hinged at 136 intermediate its ends to the lowerforward end of block 128 relative to the forward end 26 of this machine.In this position it will be noted that block 134 projects beyond block138 toward end 26 and a ramp like edge 138 is formed on the projectingedge thereof. The top of block 134 carries an aluminum plate 140 whichprojects rearwardly correspondingly with plate 130 and also has a clawpoint 142 positioned to register with point 132 on plate 130 at times ina gripping action. A permanent magnet 144 on block 134 is positioned toengage plate 130 by magnetic attraction in which position (Fig. 3)points 132 and 142 will be clamped together. Below plate 140 on block134 is an inclined baffie 146 positioned to register with the bevelededge or notch 30 on the printing surface 28 as seen in Fig. 1. On crossbrace 16 (Fig. 1) a trip roller 148 is placed which is engageable by theramp 138 on block 134 so as to move block 134 on its hinge point 136 andbreak the magnetic connection between magnet 144 and plate 130 wherebypoints 132 and 142 are separated (Fig. 5).

In describing the operation of this machine reference is first made toFig. 4 where the carriage is at its farthest point to the left or front26. A sheet of paper 126 to be printed is positioned on the printingsurface 28 and a supply of paper 34 is in position towards the rear 24as described. The carriage is manually moved to the right or its rearposition by grasping knob 150 on cross member 80 of the carriage duringwhich several operations occur simultaneously. The silk screen 90 andframe 88 are moved to a position over paper 126 and the drag on cable 94with weight 98 lowers the screen where the application of paint ismanually performed in a well known manner. As the carriage is thusmoved, baffle 146 on the gripper 124 rides up the beveled surface 30 ofthe printing board 28 (Fig. 3) which serves as a trip means for block134 so that the magnet 144 attaches itself to plate 130 and jaws 132 and142 clamp themselves on the edge of paper 126. At the same time roller112 associated with the suction foot 100 will ride up the ramp 122 onarm 120 so as to bring the foot close enough to paper stack 34 to pickup the top sheet. A depending wedge member 152 from carriage side 74(Figs. 7 and 8) will ride over shoulder 68 of lever 66 and drop down atthe rear of the inclined surface 70. Wedge 152 is hinged so it can swingupwardly toward the front but as shown will remain vertical and rigidagainst any rearward movement. A pawl 154 on the rear of carriage member74 will move to engage one of the teeth in ratchet wheel 48 (Fig. 9).

With the carriage now in position shown in Fig. 2 and with sheet 126printed, the carriage is returned to its forward position as shown inFig. 4. This also results in several simultaneous operations as follows.Gripper 124 withdraws sheet 126 from the printing board 28 until jaws132 and 142 are separated by block 134 engaging the trip roller 148(Fig. 5). Before jaws 132 and 142 release paper 126, however, wedge 152(Fig. 8) engages surface 70 of lever 66 to rock said lever on pivot 64and elevate drying plate 62 above the baffle 58. Thus any sheet on plate62 for drying will slide ofl by gravity into tray 60. Consequently,plate 62 is free and as jaws 132 and 142 release paper 126, such paperdrops onto the drying plate 62 which is now below the top of battle 58so that such baflie serves as a stop to hold the paper on the dryingplate. Side guides 156 may also be placed on plate 62 to retain thepaper against lateral displacement. During this time, the suction foothas carried another sheet of paper from stack 34 to a position over theprinting board 28 at which point the suction is released by thepenetration of flap valve 104 with a pronged member 158 carried by therear of carriage member 74. The effect of member 158 (Fig. 6) is to openvalve to the atmosphere where foot 100 releases the paper. Pa per guides160 and 162 and 164 (Figs. 2 and 4) are provided to assure accuratepositioning of the sheet to be printed. These are adjustable in a wellknown manner. It is also pointed out that as the carriage is moved fromits rearmost to forward position, pawl 154 (Fig. 9) will rotate ratchetwheel 48 one notch to correspondingly wind cable 44. This pulls thewedge 38 forwardly under wedge sides 36 to cam the paper supporting base32 upwardly so as to keep the top of stack 34 within reach of thesuction foot 100. However, due to the fact that foot 100 hasapproximately one half inch of vertical travel a substantial number ofsheets, depending upon their thickness, can be picked up withoutanyelevation of the base 32. When wedge 38 has been drawn forward as faras possible, it can be manually returned to its starting position. Itwill also be noted that the screen frame 88 is elevated by spring 92 asthe carriage is moved to its front position.

A back paper gauge 166 for stack 34 is placed on the paper base 32(Figs. 2 and 4) and comprises a bar 168 positioned transversely of sideboards 12 and 14. Knobs 170 and 172 on respective ends thereof havelower projections (not shown) which ride in the respective grooves 174and 176. Bar 166 has a notch 178 to allow clearance of arm 120.

As the process of moving the carriage as described is repeated, it willbe apparent on the return movement towards the front of this machinethat three sheets of paper are being simultaneously processed. As suchcarriage movement is started, one sheet is on the drying plate 62, oneis on the printing board'28 and one is on the stack 34. Due to thedouble heat exposure onthe drying unit 52, each sheet is quickly driedso as not to require separable stacking. Thus the carriage moves to theleft as viewed in Fig. l, the sheet on the drying plate 62 is droppedinto the tray 60, the sheet on the printing board is dropped onto thedrying plate and a new sheet from stack 34 is dropped onto the printingboard. Such an arrangement materially increases the amount of work thatcan be completed in a given time and saves a multitude of individualhandling operations formerly required.

It is submitted that the invention shown and described is aptly suitedto achieve the purposes intended and is characterized by a combinationof highly useful and mutually cooperating elements that combine theirrespec tive and proportionate functions in accomplishing the objectssought to be obtained.

It, will be understood that the phraseology employed herein is for thepurpose of description and not for limitation and that modifications andchanges in the constructionand arrangement 'of this invention can bemade withinitlie scope of what is claimed, without departing fromthe-spirit and purpose thereof. It, is thus intended to cover by theclaims, any modified forms of structure or mechanical f equivalentswhich may be reasonably ineluded within their scope.

I claim:

1. In a silk screen machine having a base and a carriage slidablethereon, an improved means for transferring paper from one position toanother, comprising, a jaw assembly including a pair of jaw members onsaid carriage for gripping a sheet of paper, one jaw member movablerelative to the other, a permanent magnet on said jaw assembly forholding said jaw members in paper gripping contact, means for breakingand reestablishing the magnetic attraction between said jaw members,said means comprising a pair of spaced trip members on said base, andsaid carriage movable to selectively place said jaw assembly in and outof contact with said trip members, one of which opens the jaw membersagainst the magnetic attraction and the other of which closes the jawmembers to reestablish the magnetic attraction.

2. In a silk screen machine having a base and a carriage slidablethereon, an improved means for transferring paper from one position toanother, comprising, a first block secured to said carriage, a metal jawmember extending from one end of said block, a second block hingedlysecured intermediate its end to the other end of said first block, a jawmember on said second block to register with the jaw member on thefirst, a permanent magnet on said second block engageable by magneticattraction with said metal jaw member to move said jaw members intopaper gripping contact, a trip roller on said base, and said carriagemovable toward said trip roller so that said second block engages thesame and rocks upon its hinge point whereby the magnetic attractionbetween said magnet and said metal jaw member is broken.

3. In a silk screen machine having a base and a carriage slidablethereon, an improved means for transferring paper from one position toanother, comprising, a first block secured to said carriage, a metal jawmember extending from one end of said block, a second block hingedlysecured intermediate its end to the other end of said first block, a jawmember on said second block to register with the jaw member on thefirst, a permanent magnet on said second block engageable by magneticattraction with said metal jaw member to move said jaw members intopaper gripping contact, first and second trip means respectively on saidbase in spaced relationship, said carriage slidable in one direction toengage said second block with one of said trip means whereby said secondblock is rocked in one direction on its hinge point to separate said jawmembers by breaking the magnetic attraction therebetween, and saidcarriage slidable in another direction to engage said second block withthe other trip means to rock said second block in the opposite directionto bring said magnet into contact with said metal jaw member wherebysaid jaw members are in gripping contact.

4. In a silk screen machine having a base and a carriage slidablethereon, an improved means for transferring paper from one position toanother, comprising, a jaw assembly including a pair of jaws pivotallydisposed on said carriage for movement toward and away from each otherto respectively grip and release a sheet of paper,

one of said jaws being magnetically attractable, a magnet. means on theother jaw, means on said .base engageable with said jaw assembly to urgeone jaw toward the other whereby said jaws are closed in paper grippingcontact by said magnet means, a second means on said base engageablewith said jaw assembly for urging one jaw away from the other to breakthe magnetic attraction, and the operation of the means for opening andclosing said jaws being eifected by the movement of said carriage inrespective opposite directions at times.

5. In a silk screen machine having a base, a printing board and acarriage slidable on said base over and away from said printing board,an improved means for removing a sheet of paper from said printingboard, comprising, a pair of jaws pivotally disposed on said carriagefor movement toward and away from each other to respectively grip andrelease a sheet of paper, one of said jaws being magneticallyattractable, a magnet means on the other jaw, one edge of said printingboard provided with a ramp-like notch, means on one jaw engageable withsaid notch when the carriage is moved toward the same for urging one jawtoward the other whereby said jaws will be clamped by said magnet aboutthe edge of a sheet of paper on said printing board, the movement of thecarriage away from said printing board causing said jaws to withdraw thepaper therefrom, a trip means on said base, and one of the jawsengageable with said trip means when the paper is clear of said printingboard to urge said jaw away from the other whereby the magneticattraction is broken and the paper is released.

6. In a machine having a base, a carriage slidable thereon in twoopposite directions respectively and a paper supporting platform, animproved means for transferring paper from said plat-form to a point ofdeposit, comprising a jaw assembly secured to and movable with saidcarriage, said jaw assembly including a first fixed jaw having a clawpoint and a second jaw having a claw point and pivotally attached tosaid first jaw so that said claws can be moved into and out of papergripping contact with each other, a permanent magnet means associatedwith said jaws to hold said claws in gripping contact when said secondjaw is within the field of magnetic attraction, said second jaw havingspaced inclined surfaces, said platform having a ramp-like notch, saidbase having a roller, and said carriage movable between said notch andsaid roller to respectively engage said inclined surfaces therewith inorder to rock said second jaw on its pivot point to selectively movesaid claw points toward and way from each other.

7. In a machine having a base and carriage slidable thereon, an improvedmeans for transferring paper from one position to another, comprising ajaw assembly secured to and movable with said carriage, said jawassembly including a pair of jaw members one of which is pivotablerelative to the other so that they can be moved into and out of papergripping contact, one of said jaw members having a metal portion and theother having a permanent magnet engageable with said metal portionwithin the field of magnetic attraction to hold said jaw members ingripping contact, said pivotable jaw member being freely movablerelative to the other outside of the field of magnetic attraction,separate respective trip means at spaced points on said base engageablewith said pivotable jaw member at respective opposite points thereonrelative to its pivot point to move the same into and out of the fieldof magnetic attraction, and said engagement of said movable jaw memberwith said trip means effected by movement of said carriage.

8. In a machine having a base and a carriage slidable thereon, animproved means for transferring paper from one position to another,comprising a jaw assembly secured to and movable with said carriage,said jaw assembly including a pair of jaw members one of which ispivotable intermediate its ends so that it can be moved into and out ofpaper gripping contact with the other, a permanent magnetic means onsaid jaw assembly as the sOlc means for holding said jaw members inpaper gripping contact, said pivotable jaw member being freely movablerelative to the other outside of the field of magnetic attraction, andsaid carriage slidable between spaced fixed points on said base to abutsaid pivotable jaw member therewith whereby said jaw member is rockedupon its pivot point to selectively move said jaw member into and out ofthe field of magnetic attraction.

References Cited in the file of this patent UNITED STATES PATENTS 12,634Mathews et a1. Apr. 3, 1855 r H 8 Smyth Ian. 12, Horvath June 11,

Nasmith July 24, Rayman Nov. 24, Aldcroftt Aug. 15, Parmele et a1 July10, McCoy June 2, Minkow Mar. 7,

Hildebrand Sept. 23, Reemelin et al. Mar. 11,

Kliever Feb. 16,

